Question: Length of pregnancies The length of human pregnancies from conception to birth varies according to a distribution that is approximately Normal with mean 266 days and standard deviation 16 days.
(a) At what percentile is a pregnancy that lasts 240 days (that's about 8 months)?
(b) What percent of pregnancies last between 240 and 270 days (roughly between 8 months and 9 months)?
(c) How long do the longest 20% of pregnancies last?